The following relates generally to wireless communication, and more specifically to low latency uplink (UL) power control.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system). A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
Wireless multiple-access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is designed to improve spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards. LTE may use OFDMA on the downlink (DL), single-carrier frequency division multiple access (SC-FDMA) on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology.
In some cases, a wireless network may utilize different transmission time interval (TTI) structures. For example, a network may utilize a TTI structure based on one or more symbol periods, which may be shorter in duration than a TTI based on a subframe structure, and which may reduce latency of communications (e.g., for hybrid automatic repeat request (HARQ) operations). However, if the power control for low-latency communications is not coordinated with non-low-latency communications—e.g., if power control for TTIs of one duration is not coordinated with power control for TTIs of a different duration—a UE may not be able to transmit data in both TTIs with sufficient power for a reliable communication link. Or, in some cases, if not properly coordinated, the combined transmit power for different TTI durations may exceed a threshold set by a base station to mitigate interference with other devices.